Average interest rates for 15-year loans fell to a historic low, while 30-year fixed-rate loans fell to a low for 2011, Freddie Mac said.

Interest rates for 15-year contracts dropped to 3.54 percent with 0.7 points, down from 3.66 percent, while interest rates for 30-year mortgages averaged 4.39 percent with 0.8 points, down from last week's 4.55 percent.

Rates for 15-year, fixed-rate mortgages a year ago stood at 3.95 percent. Rates for 30-year mortgages a year ago averaged 4.49 percent.

Frank Nothaft, Freddie Mac's vice president and chief economist, said "signs the economy was weaker than what markets had previously thought" contributed to the decline in interest rates.

"The economy grew 1.3 percent in the second quarter, which was below the market consensus forecast, and first-quarter growth was cut to less than a quarter of what was originally reported," Nothaft said.

United Press International is a leading provider of news, photos and information to millions of readers around the globe via UPI.com and its licensing services.

With a history of reliable reporting dating back to 1907, today's UPI is a credible source for the most important stories of the day, continually updated - a one-stop site for U.S. and world news, as well as entertainment, trends, science, health and stunning photography. UPI also provides insightful reports on key topics of geopolitical importance, including energy and security.

A Spanish version of the site reaches millions of readers in Latin America and beyond.

UPI was founded in 1907 by E.W. Scripps as the United Press (UP). It became known as UPI after a merger with the International News Service in 1958, which was founded in 1909 by William Randolph Hearst. Today, UPI is owned by News World Communications.